It is known that different types of neoplastic cells produce corresponding types of proteins. It is also known to examine a tissue sample to determine whether or not a particular type of protein is included in the sample, in order to make a further determination of whether or not the sample includes associated types of cancerous cells. By example, conventional techniques for performing this type of examination involve deploying a specific type of antibody and an associated fluorescent material (also referred to as a "marker") in the sample. Generally, assuming that there are cancerous cells and corresponding types of proteins included in the sample, the deployed antibody and marker become coupled to one or more of the proteins. Thereafter, using a conventional imaging system, the sample is illuminated using a specific wavelength that is known to "excite" the marker, causing the marker to fluoresce and emit fluorescent radiation of a particular wavelength. By detecting the wavelength of the emitted radiation using, for example, a radiation detector array component of the imaging system, a determination may then be made that the sample does in fact include proteins and associated cancerous cells. Otherwise, if there are no cancerous cells and corresponding proteins included in the sample, then the antibody and marker are generally not detectable using the "excitation" wavelength within the imaging system.
Unfortunately, conventional imaging systems for performing techniques such as the one described above suffer from a drawback of not being able to examine a sample for the presence of more than a single type of protein at a time, and only a single "excitation" wavelength is typically employed at a time rather than multiple excitation wavelengths. One reason for this is that conventional imaging systems typically do not include components for minimizing effects of undesired optical phenomena, such as optical scatter, which may occur in cases where multiple markers are excited using multiple excitation wavelengths. As a result, accurate determinations regarding whether or not marker emission wavelength detections indicate the presence of proteins in a sample generally cannot be made. Another shortcoming of conventional imaging systems is that these systems cannot distinguish between wavelengths emitted by different types of markers in cases where the emitted wavelengths are similar and are simultaneously emitted. For example, assuming that markers such as Lucifer Yellow CH and Calcium Green are employed in a sample being examined using a conventional imaging system, and that these markers are illuminated with wavelengths so as to cause the markers to simultaneously emit fluorescent radiation having similar wavelength values of 533 nm, the conventional imaging system cannot determine whether one or both of these markers actually fluoresced in response to being illuminated. As a result, accurate determinations regarding whether or not proteins are included in a sample cannot be made.
Being that conventional imaging systems cannot examine a tissue sample for the presence of more than a single type of protein at a time, in cases in which it is desired to determine whether or not more than one type of protein is included in a sample, it is necessary to add other individual types of markers to the sample for performing individual examinations for each type of protein being tested for. Alternatively, other tissue samples may need to be taken for the purpose of carrying out the above-described analysis for each type of protein. As can be appreciated, either one of these alternatives presents an undue burden to one who is analyzing the sample, especially in cases where it is necessary to examine the sample for the presence of many different types of cancer-related proteins.
In view of the foregoing description, it can be appreciated that it would be advantageous to provide an imaging system for performing cancer analysis of a tissue sample in a manner which overcomes the problems and shortcomings associated with prior art imaging systems.